 2004 Microchip Technology Inc.

DS21140F-page 1

24LC41

Features

• Single supply with operation down to 2.5V

• Completely implements DDC1

/DDC2 interface

for monitor identification

• Separate high speed 2-wire bus for

microcontroller access to 4K-bit Serial EEPROM

• Low-power CMOS technology

• 2 mA active current typical

•20

µA standby current typical at 5.5V

• Dual 2-wire serial interface bus

• Hardware write-protect for both ports

• Self-timed write cycle (including auto-erase)

• Page write buffer for up to 8 bytes (DDC port) or

16 bytes (4K Port)

• 100 kHz (2.5V) and 400 kHz (5V) compatibility

• 1,000,000 erase/write cycles ensured

• Data retention > 40 years

• 8-pin PDIP package

• Available for extended temperature ranges

Description

The Microchip Technology Inc. 24LC41 is a dual-port

128 x 8 and 512 x 8-bit Electrically Erasable PROM

(EEPROM). This device is designed for use in applica-

tions requiring storage and serial transmission of

configuration and control information. Three modes of

operation have been implemented:

• Transmit-only mode for the DDC Monitor Port

• Bidirectional mode for the DDC Monitor Port

• Bidirectional, industry-standard 2-wire bus for the

4K Microcontroller Access Port

Upon power-up, the DDC Monitor Port will be in the

Transmit-only mode, repeatedly sending a serial bit

stream of the entire memory array contents, clocked by

the VCLK/DWP pin. A valid high-to-low transition on

the DSCL pin will cause the device to enter the Bidirec-

tional mode, with byte-selectable read/write capability

of the memory array. The 4K-bit microcontroller port is

completely independent of the DDC port, therefore, it

can be accessed continuously by a microcontroller

without interrupting DDC transmission activity. The

24LC41 is available in a standard 8-pin PDIP package

in both commercial and industrial temperature ranges.

Package Type

Block Diagram

- Commercial (C):

0°C to

+70°C

- Industrial (I):

-40°C to

+85°C

DSCL

VCLK/DWP

MSDA

1

2

3

4

8

7

6

5

DSDA

MWP

MSCL

PDIP

EDID Table

1K Bit

4K Bit

Serial

EEPROM

MSDA

MSCL

MWP

DSDA

VCLK/DWP

DSCL

Obsolete Device